huangyhg

fire resistance of hilti chemical adhesive
hi guys,
how does hilti chemical adhesive perform when exposed to fire for a prolonged period of time. i am looking at a steel i-beam framing into a tilt-up concrete wall panel, typical we provide cast-in anchors because of the common perception that the adhesive of a chemical anchor will 'melt away' during a fire and consequently the tilt-up will fall outwards creating a potentially dangerous situation.
because of this perception we have always provided cast-in or mechanical anchors for this connection so this situation is avoided.
i was reading a hilti brochure toady that was saying that chemical adhesive has good fire-performance. is this true and does anyone else provide the detail that i have explained above of should i be keeping with the mechanical anchoring.

hilti are
asixth,
nothing against hilti, but for these type connections, i would stick with cast in ferrules, with expansion anchors for secondary connections if required. when the steel fails in a fire, it needs to be able to pull the wall inward with it rather than allowing the wall to fall outward. so i don't want to depend on adhesive anchors.
asixth,
i agree with hokie, the hilti product do come with a fire rating level, these rating are using the concrete as a heat sink, but they will fail after you get past your nominated level, then teh panel falls outward. if your in aust you will have to design them for 3 times the load of a cast-in feral to complie with the bca.
henry & hymes have a good article on tilt panels in a fire, here they give reduction factors for different items in temperature situations, for a cast-in anchor you get 0.7 reduction compared to of 0.05 to 0.01 for chemical anchor (published by hitli). i know which one i would want to bet my house on.

when in doubt, just take the next small step.

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